How to add a ssh key to remote server?

Question

In my VPS, run ssh-add -l and it returns: The agent has no identities. but I have run cat ~/.ssh/id_rsa.pub | ssh user@hostname 'cat >> .ssh/authorized_keys' cat ~/.ssh/id_rsa.pub | ssh user@hostname 'cat >> .ssh/authorized_keys' previously

I then run ssh-add ~/.ssh/authorized_keys it returns @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: UNPROTECTED PRIVATE KEY FILE! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ Permissions 0644 for '/home/deployer/.ssh/authorized_keys' are too open. It is recommended that your private key files are NOT accessible by others. This private key will be ignored. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: UNPROTECTED PRIVATE KEY FILE! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ Permissions 0644 for '/home/deployer/.ssh/authorized_keys' are too open. It is recommended that your private key files are NOT accessible by others. This private key will be ignored.

and ssh git@github.com still get report Permission denied (publickey).

Answer 1

The currently most up voted answer is plainly wrong as it fails to understand the question. OP is asking how to authorize a key on a remote server, not how to add a key to your local ssh-agent.

To add a key to a remote server use the ssh-copy-id command from your local PC:

ssh-copy-id -i path/to/key.pub username@remoteHost

This adds the public key located at path/to/key.pub with the correct permission to the server at remoteHost using username as login name. Note that this also seems to require the private key next to the public key (the path/to/key file in this example).

Answer 2

To add your ssh-key to your ssh-agent you have to add it with:

ssh-add

After that ensure your key is added:

ssh-add -l

To fix your permission problem try:

chmod 0600 ~/.ssh/authorized_keys

Answer 3

Dude, use pssh. Create a file with all the hostnames you want to add the file to, then run something like:

pssh -h [hostsfile] -P 'echo "sshkeystringBLARG etc..." >> /home/[user]/.ssh/authorized_hosts'

You can modify the cmd accordingly and off you go.

Enjoy